# Extending Sources
Essential Addons for YOOtheme Pro uses best practices when extending YOOtheme Pro, becoming in an essence a core feature. If you know how to extend YOOtheme Pro, you already know how to extend Essential Addons. However we invite you to visit the YOOtheme Pro Developers Modules Guide (opens new window) for reference and up to date best practices.
The Sources addon is encapsulated as a YOOtheme Pro Module named
source located at
plugins/system/yooessentials/modules in Joomla and
wp-content/plugins/yooessentials/modules in WordPress.
The main advantages of YOOessential sources is that they can offer different "instances" of the same source type. For example, our
CsvSource allows the administrator to create different, individual Dynamic Content Sources, one for each CSV file he wants. All of these use the same
Source class, that dinamically registers new Dynamic Contend Sources based on the admin configurations.